KR102522246B1 - Eccentric Butterfly Valve - Google Patents

Abstract

The eccentric butterfly valve 11 is rotatable around a rotational axis perpendicular to the flow path axis of the valve body 13 via a valve shaft and a valve body 13 in which an internal flow path 13a extending in the flow path axial direction is formed. A supported valve body and a seat ring 17 installed on the inner circumference of the internal passage are provided. The valve shaft is constituted by the first valve shaft 31 and the second valve shaft 33 . The valve body is formed with a through hole 39 through which the first valve shaft is inserted and a bottomed shaft hole for supporting the second valve shaft, and a fitting hole 35 and a locking groove 37 are formed in the valve body. And, the fitting part (31a) installed at the front end of the first valve shaft is fitted to the fitting hole, and the locking part installed at the front end of the second valve shaft is inserted into the locking groove in a direction perpendicular to the rotation axis.

Description

Eccentric Butterfly Valve

The present invention relates to an eccentric butterfly valve used in fluid transport pipelines in various industries and which opens and closes a flow path by rotating a valve body.

In various industries such as chemical plants, semiconductor manufacturing fields, food fields, and bio fields, butterfly valves are used to open and close passages through which various fluids flow, and to control them. In a butterfly valve, a disk-shaped valve body rotatably supported by a valve shaft on a valve body is disposed in a tubular flow path formed in a valve body, and a handle or an actuator connected to the valve shaft By rotating the valve shaft to separate the outer circumferential edge of the valve body with respect to the annular seat member installed between the inner circumferential surface of the flow path or the outer circumferential edge of the valve body and the valve body.籬), opening and closing of the flow path is performed.

Since the butterfly valve is structured as described above, even when the valve is fully opened, the main surface of the valve body (the surface facing the flow path axial direction when the valve is closed) ) is located at the center of the flow path of the valve body so that it is almost parallel to the direction of the flow path. Therefore, the valve body reduces the flow path area and becomes resistance to the fluid, lowering the capacity coefficient such as Cv value. In particular, in an eccentric butterfly valve in which the stem is connected to the valve body so that the rotation axis is offset from the central axis of the valve body in the thickness direction of the valve body, since the valve body is thick in construction, the valve body It greatly affects the reduction of area or the increase of fluid resistance. As one of the countermeasures against this problem, as described in Patent Literature 1 and Patent Literature 2, for example, a groove portion extending in a straight line perpendicular to the axis of rotation is provided on the main surface of the valve body, and the valve body A butterfly valve in which the cross section of is formed in a substantially C-shape to increase the passage area at the time of full opening and to reduce passage resistance has been proposed.

Patent Document 1: Japanese Patent Laid-Open No. 7-113472 Patent Document 2: Japanese Unexamined Publication No. 60-188272

As described above, it is advantageous to reduce the thickness of a portion of the valve body by providing a groove portion to increase the passage area or decrease the passage resistance. However, when the valve body is supported by the valve body by passing the valve shaft through the valve body, the valve shaft is exposed and becomes fluid resistance. Further, if the valve shaft is not exposed, the groove cannot be deepened and the opening area cannot be sufficiently increased. Therefore, the effect of increasing the capacity coefficient is reduced. For this reason, like the butterfly valve described in Patent Literature 1 or Patent Literature 2, a structure in which the valve element is rotatably supported in the valve body by two valve shafts has been adopted.

In the above structure, in view of assembly, fitting holes are provided in the upper and lower parts of the valve body, and through-holes are provided in the upper and lower parts of the valve body, and through the upper and lower through-holes, the fitting holes of the valve body are provided. The valve shaft is fitted and fixed to support the valve body within the valve body, and an annular rubber seal member is provided between the outer circumferential surface of the valve shaft and the inner circumferential surface of the through hole in order to prevent leakage of fluid in the passage to the outside. The arrangement method has been adopted. However, while this method has a simple structure and can be manufactured at low cost, there are cases in which the fluid in the flow path leaks to the outside through the sealing parts of the upper and lower through-holes, and thus the sealing performance cannot be said to be sufficient.

Accordingly, an object of the present invention is to solve the problems existing in the prior art, to provide an eccentric butterfly valve that makes it possible to suppress leakage of fluid in a flow path to the outside while realizing an improvement in capacity coefficient. there is.

In view of the above object, the present invention provides a valve body in which an internal flow path extending in the flow path axis direction is formed, and a valve body through a valve shaft within the internal flow path perpendicular to the flow path axis. A disk-shaped valve body rotatably supported around a rotational axis, and a seat ring installed on an inner circumference of the inner passage, wherein the seat ring is provided when the valve is closed. A seal surface for sealing the inner flow path is formed between the outer circumferential edge of the valve body, and the rotation axis is eccentric from the seal surface in the direction of the flow path axis. An eccentric butterfly valve, wherein the valve shaft is constituted by a first valve shaft and a second valve shaft, extends through the valve body from an outer circumferential surface to the inner passage, and rotates the first valve shaft. A through shaft hole to be inserted and a bottomed shaft hole for rotatably supporting the second valve shaft are formed, respectively, at opposite positions on the rotation axis in the valve body, fitting holes and an engaging groove formed therein, and a fitting part installed at the distal end of the first valve shaft extending through the through hole is fitted into the fitting hole so that the first valve shaft cannot rotate with the valve body. While being connected to, the second valve shaft rotates with the valve body by being inserted into the locking groove in a direction perpendicular to the axis of rotation by a locking portion installed at the front end of the second valve shaft protruding from the shaft hole with the bottom. Provided is an eccentric butterfly valve adapted to be disconnected.

In the eccentric butterfly valve, the valve body is rotatably supported by the valve body by two valve shafts, and since the valve shaft does not extend through the valve body, a deep groove portion can be formed in the central portion of the valve body. In addition, it is possible to improve the capacity coefficient by increasing the opening area when fully opened. Further, by inserting the valve body into the internal passage in a direction perpendicular to the axis of rotation, the locking portion of the second valve shaft protruding from the shaft hole in the state where the second valve shaft is inserted into the bottomed shaft hole is inserted into the locking groove of the valve body. By inserting it, it is possible to connect the second valve shaft and the valve body non-rotatably. After that, the first valve shaft and the valve body can be non-rotatably connected by passing the first valve through the through shaft hole and fitting the fitting portion of the first valve shaft into the fitting hole of the valve body. With this structure, the valve body and the valve body are formed in such a way that the valve body is rotatably supported in the internal flow path of the valve body without using one of the shaft holes for pivotally supporting the valve shaft on the valve body as a through shaft hole. assembly is possible. Therefore, there is no need to make one of the shaft holes formed in the valve body as a through shaft hole. As a result, it is possible to reduce the number of places where the fluid in the passage can leak to the outside, and to suppress the leakage of the fluid in the passage to the outside through the shaft hole.

In one embodiment of the eccentric butterfly valve, the locking portion is connected to a shaft portion of the second valve shaft located in the bottomed shaft hole and extends in a direction perpendicular to the rotation axis line. part, the locking groove has a shape complementary to the locking portion. In this case, it is preferable that the rail-shaped portion has a wedge-shaped cross section that widens from the connection portion with the shaft portion toward the distal end.

In addition, it is preferable that the axis of rotation be positioned eccentrically from the center of the internal passage.

In addition, an annular seal adjacent to the opening of the through shaft hole into the inner flow path, sealing the inner circumferential surface of the through shaft hole and the outer circumferential surface of the first valve shaft. ) It is preferable that a seal member is disposed, and a flange portion is provided at an outer end portion of the first valve shaft, and an annular concave portion is formed at an outer circumferential end portion of the through hole. It is more preferable that an annular flat seal member is held between the annular concave portion and the flange portion.

According to the eccentric butterfly valve of the present invention, the capacity coefficient can be improved by increasing the opening area when fully opened by providing the groove in the valve body. In addition, since the assembly of the valve body and the valve body is possible by using only one side of the valve shaft hole installed in the valve body as a through shaft hole, the place where the fluid in the flow path may leak to the outside is reduced, and the flow path through the shaft hole is reduced. It can suppress the leakage of internal fluid to the outside.

[Figure 1] is a longitudinal cross-sectional view showing the overall configuration of a butterfly valve according to the present invention.
[Fig. 2] A side view of the butterfly valve shown in Fig. 1 viewed from the right side.
Fig. 3 is a perspective view of a valve element of the butterfly valve shown in Fig. 1;
Fig. 4a is a plan view of the valve body shown in Fig. 3 as seen from the right side in Fig. 1;
Fig. 4B is a top view of the valve element shown in Fig. 4A as viewed from above in Fig. 4A.
Fig. 4c is a bottom view of the valve element shown in Fig. 4a as viewed from the bottom in Fig. 4a.
[Fig. 5] A cross-sectional view in the direction of the arrow viewed from above along the line IV-IV in Fig. 4A.
Fig. 6A is a perspective view of a lower second valve shaft that holds the valve body of the butterfly valve shown in Fig. 1;
Fig. 6B is a side view of a lower second valve shaft holding a valve body of the butterfly valve shown in Fig. 1 as seen in the direction of arrow A.
Fig. 7 is a partial longitudinal sectional view of the butterfly valve showing the upper first valve shaft holding the valve body of the butterfly valve shown in Fig. 1;
Fig. 8a is an explanatory diagram showing an assembling procedure between a valve body and a valve body of the butterfly valve shown in Fig. 1;
Fig. 8b is an explanatory diagram showing an assembly procedure between a valve body and a valve body of the butterfly valve shown in Fig. 1;
Fig. 8c is an explanatory diagram showing an assembly procedure between a valve body and a valve body of the butterfly valve shown in Fig. 1;
Fig. 8D is an explanatory diagram showing an assembly procedure between a valve body and a valve body of the butterfly valve shown in Fig. 1;
Fig. 8E is an explanatory diagram showing an assembly procedure between a valve body and a valve body of the butterfly valve shown in Fig. 1;

Hereinafter, an embodiment of the butterfly valve 11 according to the present invention will be described with reference to the drawings.

First, with reference to FIGS. 1 and 2, the overall configuration of the butterfly valve 11 according to the present invention will be described.

The butterfly valve 11 includes a hollow cylindrical valve body 13 in which an internal flow path 13a extending in the axial direction of the flow path is formed, and a valve body 13 disposed in the internal flow path 13a and rotatable to the valve body 13. For fixing the valve body 15 in the shape of a substantially disk, the annular seat ring 17 installed on the inner circumference of the inner passage 13a, and the seat ring 17 to the valve body 13 An annular seat stopper 19 is provided, and the valve seat portion 17a formed on the outer periphery of the valve body 15 and the seat ring 17 is separated, thereby forming an internal flow path 13a. ) can be opened and closed.

The periphery of the downstream end of the flow path axial direction of the internal flow path 13a of the valve body 13, that is, the outer periphery of the internal flow path 13a on the downstream side of the flow path axial direction of the valve body 13. An annular concave portion 21 extending in the radial direction to a diameter substantially equal to the outer diameter of the annular seat stopper 19 is formed in the outer portion, and this annular concave portion is formed. A seat ring 17 and a seat stopper 19 are fitted to the portion 21. The seat stopper 19 is composed of an annular retainer body 19a and an annular retainer cap 19b. A stepped portion 23 (see Fig. 7) is formed on the retainer body 19a, and a fixed portion of the seat ring 17 between the retainer cap 19b and the stepped portion 23 is formed on the stepped portion 23. The retainer cap 19b and the fixing portion 17b of the seat ring 17 are accommodated so as to dispose the 17b. With this configuration, the retainer body 19a is fixed to the annular concave portion 21 in an appropriate manner, and the retainer cap 19b disposed on the side surface of the annular concave portion 21 in the flow path axial direction and the retainer body 19a ), the seat ring 17 can be fixed to the annular concave portion 21 by holding the fixing portion 17b of the seat ring 17 between them.

In addition, it is preferable that the retainer cap 19b is disposed in such a way that its inner periphery protrudes into the inner passage 13a.

As a method of fixing the retainer body 19a to the annular concave portion 21, for example, a bayonet method as disclosed in Japanese Unexamined Patent Publication No. 11-230372 can be employed. In this case, a plurality of circular arc-shaped projections protruding in the radial direction are formed at equal intervals in the circumferential direction on the outer circumferential surface of the valve body 13 side of the retainer body 19a, and a circular arc is formed on the outer circumference of the annular concave portion 21. An arc-shaped cutout formed to accommodate the shaped protrusion and an engagement extending in a form that guides the arc-shaped protrusion in the circumferential direction from the side surface side in the flow path axial direction of the arc-shaped cutout A groove is provided, and the arc-shaped projection of the retainer body 19a is fitted into the arc-shaped cutout of the annular concave portion 21 so that the arc-shaped projection abuts against the side surface of the flow passage axial direction of the annular concave portion 21. ), the retainer body 19a is rotated in the circumferential direction, the arc-shaped projection is guided along the engagement groove, and the arc-shaped projection and the engagement groove are engaged. ) can be fixed.

The seat ring 17 is made of an elastic material and has a valve seat portion 17a and a fixing portion 17b. The valve seat portion 17a is formed when the seat ring 17 is installed in the annular concave portion 21 in a state where the fixing portion 17b is held between the retainer body 19a and the retainer cap 19b. , It is formed so as to protrude into the internal passage 13a. Suitable elastic materials for forming the seat ring 17 include rubber elastic materials such as butyl rubber (BR), chloroprene rubber (CR), ethylene propylene diene rubber (EPDM), and fluororubber (FRM); polytetrafluoroethylene (PTFE); ), and fluororesin-coated rubber elastic bodies such as PTFE.

The valve element 15 has two opposing main surfaces 15a and 15b and an outer periphery 15c extending annularly so as to connect between the two main surfaces 15a and 15b. As shown in Fig. 3, on one main surface 15a of the valve element 15, a groove 25 extending through and extending in a direction crossing the rotation axis R (preferably a direction orthogonal to it) is provided. there is. Both side walls 25a, 25b of the groove portion 25 are convex curved surfaces extending convexly toward each other toward the rotation axis R, as shown in FIG. 2 or FIG. 4A. is formed In addition, by forming the groove portion 25 as described above on one main surface 15a of the valve element 15, on both sides of the rotation axis R direction with the groove portion 25 therebetween, the outer edge residual portion ( An external control unit (27) (27a, 27b) is formed. As shown in FIGS. 4B and 4C , the outer edge retaining portion 27 preferably has a convex curved surface extending convexly in a direction away from the rotation axis R.

By providing the groove portion 25 as described above, when the valve body 15 is rotated to the fully open state, the opening area in the internal flow passage 13a increases by the amount of the groove portion 25, and the capacity coefficient Cv increases. It increases. In addition, the present inventor forms the side walls 25a and 25b of the groove portion 25 as convex-shaped curved surfaces that extend convexly toward each other toward the rotation axis R to form a throttle portion, or a groove portion ( By forming the outer edge residual portions 27a and 27b formed on both sides of 25) to have a convex curved surface extending in a convex shape in a direction away from the rotation axis R, generation of vortices is suppressed and pressure found to reduce losses. This makes it possible to obtain the effect of improving the capacity coefficient Cv.

Further, as shown in Fig. 5, a spherical concave portion (hereinafter also referred to as a "dimple") 29 is formed in the central portion of the other main surface 15b of the valve element 15. has been By providing such a spherical concave portion 29, generation of vortices is similarly suppressed, and the effect of improving the capacity coefficient by reducing the pressure loss can be obtained.

A valve element valve seat surface 15d is formed on the outer periphery 15c of the valve element 15, and the valve element valve seat surface 15d is formed by rotating the valve element 15 around the rotation axis R. By press-contacting the valve seat portion 17a of the seat ring 17, a seal surface for sealing between the valve element valve seat surface 15d and the valve seat portion 17a is formed, The flow path 13a is closed to bring it into a valve closed state. It is preferable that the valve body valve seat surface 15d has the same shape as a part of the spherical surface.

In the butterfly valve 11 of the illustrated embodiment, the valve element 15 is rotatably supported by the valve body 13 by the first valve shaft 31 and the second valve shaft 33. At opposite positions in the direction of the rotation axis R of the valve element 15, a fitting hole 35 for coupling with the first valve shaft 31 and the second valve shaft 33 are provided. A locking groove 37 for connecting with is provided.

The first valve shaft 31 is rotatably inserted into and supported by a first shaft hole 39 formed in the valve body 13 in a form extending along the rotational axis R, and , The second valve shaft 33 is inserted into the second shaft hole 41 formed to face the first shaft hole 39 through the internal passage 13a along the rotational axis R, and is rotatably supported. has been

When the valve body 15 is supported on the valve body 13 by one valve shaft, the valve shaft needs to pass through the valve body 15. Therefore, if the deep groove portion 25 is provided to increase the opening area, especially in the eccentric butterfly valve, the valve shaft is easily exposed to the outside, and the valve shaft blocks the internal passage. As a result, the effect of increasing the opening area by the groove portion 25 is no longer obtained. In contrast, in the butterfly valve 11, the valve body 15 is rotatably supported by the valve body 13 by two valve shafts, the first valve shaft 31 and the second valve shaft 33. Therefore, even if the deep groove portion 25 is provided, the first valve shaft 31 and the second valve shaft 33 can be prevented from being exposed to the internal passage 13a. As a result, it becomes easy to obtain the effect of increasing the opening area by the groove part 25.

The first shaft hole 39 is a through shaft hole that extends from the outside through the valve body 13 in the direction of the rotation axis R to the internal passage 13a, and both ends protrude from the first shaft hole 39. The 1st valve shaft 31 is inserted in the 1st shaft hole 39 so that rotation is possible. A handle or drive unit (not shown) can be installed on one end (upper end in FIG. 1 ) of the first valve shaft 31 protruding outward to operate or drive the valve body 15 . Further, at the other end (lower end in FIG. 1 ) of the first valve shaft 31 protruding into the internal passage 13a, a fitting portion 31a having a shape complementary to the fitting hole 35 is formed. The fitting hole 35 of the valve body 15 and the fitting portion 31a are non-rotatably fitted around the rotational axis R. For example, by forming the fitting hole 35 of the valve body 15 and the fitting part 31a of the first valve shaft 31 so as to have a polygonal shape, the fitting hole 35 and the fitting part 31a ) can be connected with no rotation.

On the other hand, the second shaft hole 41 is a bottomed shaft extending in the direction of the rotation axis R from the inner passage 13a of the valve body 13 (ie, a shaft hole that is not penetrated), and one side The 2nd valve shaft 33 is inserted into the 2nd shaft hole 41 so that an edge part protrudes from the 2nd shaft hole 41, and is supported so that rotation is possible. The 2nd valve shaft 33 is connected to the axial part 33a so that it protrudes from the 2nd shaft part 33a supported rotatably in the 2nd shaft hole 41 and the 2nd shaft part 41, and is formed, It includes a locking portion (係止部) 33b, and the locking portion (33b) is fitted to the locking groove (37). In detail, as shown in FIGS. 6A and 6B , the locking portion 33b is formed as a rail-shaped portion extending in a direction perpendicular to the rotation axis R, and one end of the rail-shaped portion is It protrudes and extends from the outer circumferential surface of the shaft portion 33a in a direction perpendicular to the rotational axis R, and the second valve shaft 33 has a substantially L-shape. In addition, as shown in FIG. 4A, the engaging groove 37 of the valve body 15 is formed so as to have a complementary shape to the rail-shaped portion, and the valve body 15 and the second valve shaft 33, By inserting the locking portion 33b, which is a rail-shaped part, into the locking groove 37 of the valve body 15 in a direction perpendicular to the rotation axis R, it is connected non-rotatably around the rotation axis R. there is. It is preferable that the hooking part 33b, which is a rail-shaped part, has a wedge-shaped cross section that spreads from a base, which is a connecting part with the shaft part 33a, toward the tip. By having such a wedge shape, it is possible to prevent the valve element 15 from coming off in the direction of the rotational axis R from the second valve shaft 33. However, the cross-sectional shape of the locking portion 33b is not limited as long as the valve element 15 and the second valve shaft 33 can be connected non-rotatably, and may be polygonal, circular or elliptical. .

In this way, the second shaft hole 41 supporting the second valve shaft 33 so as to be able to rotate is a bottomed shaft hole that does not penetrate the valve body 13, so that the internal passage 13a Holes penetrating to the outside are reduced, so that the sealability of the internal flow passage 13a is improved, and the possibility of the fluid in the internal flow passage 13a flowing out to the outside can be reduced.

In addition, as shown in FIG. 1, in order to prevent the fluid in the internal passage 13a from entering the bottomed fitting hole 35 or the second shaft hole 41, the first valve shaft 31 ) or the outer circumferential surface of the shaft portion 33a of the second valve shaft 33, the inner circumferential surface of the fitting hole 35 near the opening to the inner passage 13a or the inside of the inner circumferential surface of the second shaft hole 41 Annular seal members 43 and 45 are disposed in an annular groove provided at a position relative to the vicinity of the opening to the passage 13a, and between the inner circumferential surface of the fitting hole 35 and the outer circumferential surface of the first valve shaft 31 and It is designed to seal between the inner circumferential surface of the 2nd shaft hole 41 and the outer circumferential surface of the shaft part 33a of the 2nd valve shaft 33. In addition, in order to prevent the fluid in the internal passage 13a from leaking out through the first shaft hole 39, which is a through hole, a first shaft hole 39 is formed on the outer circumferential surface of the first valve shaft 31. Annular seal members such as O-rings made of rubber elastic material in annular grooves provided at a plurality of positions (three positions in the illustrated embodiment) including positions relative to the vicinity of the opening to the internal passage 13a of 47a, 47b and 47c are arranged to seal between the inner circumferential surface of the first shaft hole 39 and the outer circumferential surface of the first valve shaft 31. In addition, as shown in detail in FIG. 7 , a flange portion 31b is provided near the end of the first valve shaft 31 on the opposite side to the fitting portion 31a, and the first valve body 13 An annular concave portion 13b for accommodating the flange portion 31b is provided around the opening to the outside of the shaft hole 39, and the surface facing the flange portion 31b at the annular concave portion 13b (hereinafter, An annular flat seal member 47d made of a rubber elastic material is fitted into the annular groove provided on the bottom surface. The sealing member 47d arranged in this way seals between the flange portion 31b and the bottom surface of the annular concave portion 13b, so that even if the fluid in the internal flow path 13a penetrates into the first shaft hole 39, , leaking to the outside from the first shaft hole 39 is prevented. This seal structure is particularly effective when a harmful fluid flows through the internal passage 13a. In addition, the flat seal member 47d is applied to the inner circumferential surface of the first shaft hole 39 and the first valve shaft 31 in addition to the pressure deformation between the flange portion 31b and the bottom surface of the annular concave portion 13b. ), if the fluid leaks through the outer circumferential surface, it is deformed by the fluid pressure and further pressed against the bottom surfaces of the flange portion 31b and the annular concave portion 13b, so that the sealability is higher, and the leakage of the fluid can be prevented. also indicates

The butterfly valve 11 of the illustrated embodiment is a double eccentric butterfly valve having a double eccentric structure. 1 and 2, in the double eccentric butterfly valve 11, the valve seat surface 15d of the valve body 15 and the valve seat portion of the seat ring 17 ( 17a) the valve seat portion 17a of the seat ring 17 so that the center of the flow path axial direction of the seal surface formed between them is eccentric from the rotation axis R of the valve body 15 in the flow path axial direction. , the valve element valve seat surface 15d, the first valve shaft 31 and the second valve shaft 33 are provided. Further, as shown in detail in FIG. 2 , a central axis O extending parallel to the rotation axis R so that the rotation axis R of the valve body 15 passes through the center of the cross section of the internal passage 13a. The first valve shaft 31 and the second valve shaft 33 are connected to the valve body 15 so as to be spaced apart from each other by a distance d within the same cross section. With this configuration, the valve body 15 is separated from the seat ring 17 at a slight rotational angle due to the cam action caused by the eccentricity when the valve is opened and closed, so that the seat ring 17 and the valve body 15 ) is small, and it becomes possible to reduce the operating torque while reducing the wear of the seat ring 17.

In addition, as described above, since the double eccentric butterfly valve 11 is configured so that the rotational axis R is eccentric from the central axis O of the internal passage 13a, the valve body 15 The maximum width in the direction of the rotation axis R is different between one side and the other side in the radial direction with the rotation axis R interposed therebetween. Using this fact, in the double eccentric butterfly valve 11 of the illustrated embodiment, the retainer cap 19b is arranged so that the inner periphery protrudes into the inner passage 13a. As a result, when the valve body 15 is rotated from the valve closed state to the valve open state, the outer periphery 15c does not interfere with the retainer cap 19b during rotation in one direction around the rotation axis R, and the valve so that the body 15 can rotate and the outer periphery 15c interferes with the retainer cap 19b during rotation in the other direction around the rotation axis R, so that the valve body 15 cannot rotate, By setting the amount of protrusion of the retainer cap 19b into the internal passage 13a, it is possible to regulate the direction of rotation of the valve element 15 from the fully closed state.

In addition, the valve body 13, the valve body 15, the seat stopper 19, the first valve shaft 31, and the second valve shaft 33 are made of a metal material, a resin material, or a resin material depending on the application. It can be formed of a coated metal material, a metal material insert-molded by an injection molding method, or the like.

Next, a method of assembling the butterfly valve 11 will be described with reference to FIGS. 8A to 8E.

First, as shown in FIG. 8A, the shaft portion 33a of the second valve shaft 33 is rotatably inserted into the second shaft hole 41 of the valve body 13. At this time, the rail-shaped part of the locking portion 33b of the second valve shaft 33 extends in the flow path axial direction and protrudes from the circumferential surface of the shaft portion 33a in a direction perpendicular to the rotation axis R. The second valve shaft 33 is disposed such that the side to be used faces the mounting side of the seat ring 17 (the annular concave portion 21 side).

Next, as shown in FIG. 8B, from the opposite side of the annular concave portion 21 and the flow path axial direction, in the state where the locking groove 37 of the valve body 15 is directed toward the valve body 13 side, in the flow path axial direction. By inserting the valve body 15 into the internal passage 13a of the valve body 13, the locking portion 33b of the second valve shaft 33 and the locking groove 37 of the valve body 15 are interposed. Aligned, the locking portion 33b is accommodated in the locking groove 37 until the locking portion 33b reaches the end of the locking groove 37. Furthermore, as shown in FIG. 8C , by inserting the first valve shaft 31 into the first shaft hole 39, the fitting portion 31a of the first valve shaft 31 is made non-rotatable as a valve element. It fits into the fitting hole 35 of (15). Thereby, the valve body 15 is supported in the internal passage 13a of the valve body 13 so as to be able to rotate around the rotation axis R.

Inserting the valve element 15 from the side close to the second valve shaft 33 by inserting the valve element 15 into the internal passage 13a in a state where the second valve shaft 33 is disposed in the above-described direction. It becomes possible, and the work becomes easy.

Next, as shown in FIG. 8D, the valve body 15 is rotated by 180° around the rotational axis R in the internal passage 13a, and as shown in FIG. 8E, the valve body 15 The valve seat surface 15d of the valve body is disposed toward the side where the seat ring 17 is mounted, that is, toward the annular concave portion 21 side. After that, the seat ring 17 is attached to the annular concave portion 21 by the seat stopper 19, and assembly of the butterfly valve 11 is completed.

In this way, in the butterfly valve 11, the second valve shaft 33 is rotatably supported in the non-pierced second shaft hole 41, and the valve element is provided in the flow path axial direction in the internal flow path 13a. By inserting (15), the locking portion 33b of the second valve shaft 33 and the locking groove 37 of the valve body 15 are fitted so that the second valve shaft 33 and the valve body 15 are fitted. ) to connect. Therefore, assembling of the valve body 15 to the valve body 13 is facilitated, the method of assembling the butterfly valve is simplified, and the effect of reducing the assembly cost is obtained. In addition, since the second shaft hole 41 is not a penetrating shaft hole, leakage of the fluid in the internal flow path 13a to the outside through the second shaft hole 41 is eliminated, and the sealing of the internal flow path 13a is improved. It improves.

In the above, the butterfly valve 11 according to the present invention has been described with reference to the illustrated embodiment, but the present invention is not limited to the illustrated embodiment. For example, in the above embodiment, the present invention is explained based on the embodiment in which the present invention is applied to the double eccentric butterfly valve 11, but the application of the present invention is limited to the double eccentric butterfly valve Instead, it is also possible to apply the present invention to a butterfly valve of a single eccentric type or a multi-eccentric type.

11 Butterfly valve
13 valve body
13a internal flow path
15 valve body
15c outer periphery
15d valve body valve seat surface
17 seat ring
17a valve seat part
31 first valve shaft
31a fitting part
33 2nd valve shaft
33a shaft
33b hanging part
35 mating hole
37 catch groove
39 No. 1 soccer hole
41 2nd soccer hole
47a, 47b, 47c annular seal member
47d plane seal member

Claims (8)

A valve body in which an internal flow path extending in the flow path axis direction is formed, and the valve body rotates around a rotation axis perpendicular to the flow path axis through a valve shaft in the internal flow path. A disc-shaped valve body supported as possible and a seat ring installed on an inner circumference of the inner passage, wherein the seat ring is provided on an outer circumferential edge of the valve body when the valve is closed. An eccentric type butterfly valve in which a seal surface sealing the internal flow path is formed between the part and the pivot axis is positioned eccentrically from the seal surface in the direction of the flow path axis,
The valve shaft is composed of a first valve shaft and a second valve shaft, extends through the valve body from the outer circumferential surface to the inner passage, and is rotatably inserted through the first valve shaft. A shaft hole and a bottomed shaft hole for pivotably supporting the second valve shaft are formed, and fitting holes and locking grooves are formed at opposite positions on the rotation axis in the valve body, respectively. is formed, and the first valve shaft is non-rotatably connected to the valve body by fitting a fitting portion installed at the distal end of the first valve shaft extending through the through shaft hole and fitting into the fitting hole, and the bottom The second valve shaft is non-rotatably connected to the valve body by being inserted into the locking groove in a direction perpendicular to the pivot axis, provided at the front end of the second valve shaft protruding from the shaft hole. Characterized by an eccentric butterfly valve. The method of claim 1,
The locking portion is a rail-shaped part connected to a shaft portion of the second valve shaft located in the bottomed shaft hole and extending in a direction perpendicular to the pivot axis, and the locking groove is complementary to the locking portion. An eccentric butterfly valve with a red shape. The method of claim 2,
The eccentric type butterfly valve, wherein the rail-shaped portion has a wedge-shaped cross section that widens from a connecting portion with the shaft portion toward a distal end. The method of claim 1,
The eccentric butterfly valve, wherein the axis of rotation is located eccentrically from the center of the internal passage. The method of claim 2,
The eccentric butterfly valve, wherein the axis of rotation is located eccentrically from the center of the internal passage. The method of claim 3,
The eccentric butterfly valve, wherein the axis of rotation is located eccentrically from the center of the internal passage. The method according to any one of claims 1 to 6,
An eccentric type butterfly valve, wherein an annular seal member for sealing an inner circumferential surface of the through shaft hole and an outer circumferential surface of the first valve shaft is disposed adjacent to an opening of the through shaft hole into the inner flow path. The method of claim 7,
A flange portion is provided at an outer end of the first valve shaft, an annular concave portion is formed at an outer circumferential end portion of the through hole, and an annular flat surface is formed between the annular concave portion and the flange portion. An eccentric butterfly valve in which a seal member is sandwiched.

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